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Diels-Alder addition of butadiene to various thiocarbonyl(R2C?SOn,n=0-2) heterodienophiles andendo-lone pair effect in heterocumulene

1997; Wiley; Volume: 10; Issue: 10 Linguagem: Inglês

10.1002/(sici)1099-1395(199710)10

1099-1395

Mariappan Manoharan, Ponnambalam Venuvanalingam,

Chemistry and Chemical Engineering

Journal of Physical Organic ChemistryVolume 10, Issue 10 p. 768-776 Research Article Diels–Alder addition of butadiene to various thiocarbonyl(R2CSOn, n=0–2) heterodienophiles and endo-lone pair effect in heterocumulene Mariappan Manoharan, Mariappan Manoharan Department of Chemistry, Bharathidasan University, Tiruchirappalli-620 024, Tamil Nadu, IndiaSearch for more papers by this authorPonnambalam Venuvanalingam, Corresponding Author Ponnambalam Venuvanalingam Department of Chemistry, Bharathidasan University, Tiruchirappalli-620 024, Tamil Nadu, IndiaDepartment of Chemistry, Bharathidasan University, Tiruchirappalli-620 024, Tamil Nadu, India===Search for more papers by this author Mariappan Manoharan, Mariappan Manoharan Department of Chemistry, Bharathidasan University, Tiruchirappalli-620 024, Tamil Nadu, IndiaSearch for more papers by this authorPonnambalam Venuvanalingam, Corresponding Author Ponnambalam Venuvanalingam Department of Chemistry, Bharathidasan University, Tiruchirappalli-620 024, Tamil Nadu, IndiaDepartment of Chemistry, Bharathidasan University, Tiruchirappalli-620 024, Tamil Nadu, India===Search for more papers by this author First published: 04 December 1998 https://doi.org/10.1002/(SICI)1099-1395(199710)10:10 3.0.CO;2-6Citations: 7AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Abstract Diels–Alder reactions of various thiocarbonyl S-oxides and thiocarbonyl S,S-dioxides with buta-1,3-diene were studied by semiempirical AM1 and PM3 methods. Calculations show that the reactions of such unsymmetrical heterodienophiles pass through asynchronous transition states (TSs) with C=S π* involved in the reaction. Calculated activation energies indicate that the reactivity of these heterodienophiles, viz. R2C=S, R2C=SO and R2C=SO2, decrease gradually with successive addition of oxygen atoms to the thiocarbonyl sulfur. This is in good agreement with the experimental observations. The predictions based on LUMO and deformation energies show that the above reactivity trend corresponds to a gradual destabilization of LUMO of the dienophile and increase in deformation energy of both diene and dienophile with increase in the number of oxygen atoms around sulfur. Thiophosgene and their S-oxides in Diels–Alder reactions are found to be less reactive than the parent analogues. Monosubstituted (Z/E)-sulfines react with buta-1,3-diene to form cis and trans products through closely lying TSs. Calculations predict that (E)-sulfine has a higher reactivity than the Z-isomer, in reasonable agreement with experimental results. © 1997 John Wiley & Sons, Ltd. Citing Literature Volume10, Issue10October 1997Pages 768-776 RelatedInformation